I have already purchased the Fender Rumble 500 2x10 combo in my quest to move away from my old heavy Trace Elliott bass rig. The Rumble combo is highly regarded but when you want to move a bit more air on a bigger or outdoor stage you'll need more speakers.
This 2x10 ext cabinet is exactly the same dimensions as the combo - the two look great when stacked, and it brings the combo speakers nearer to ear level so you can hear yourself better on stage.
Interestingly this ext cab is slightly heavier than the combo, due to the heavier plywood used in the ext cab. Also bear in mind Fender don?t supply covers for this cab or the combo.